Improvement in carriage-jacks



1.1;. BAKER. Carriage-lack.

' Patented A 'ri'|13,1875.

THE GRAPHIC C0.PHOTO.-LlTH-39 8L4! PARK PLAOghLY.

. fl m /V w. b a n JOHN G. BAKER, OF PHILADELPHIA,

PENNSYLVANIA, ASSIGNOR TO THE ENTERPRISE MANUFACTURING COMPANY OF PENNSYLVANIA, OF SAME PLACE.

IMPROVEMENT IN CARRIAGE-JACKS- Specification forming part of Letters Patent No. 162,009, dated April 13, 1875; application filed March 4, 1875.

To all whom it may concern:

Be it known that I, JOHN G. BAKER, of Philadelphia, Pennsyl\-'ania, have invented an Improved Carriage-Jack, of which the following is a specification The object of my invention is to construct a simple and effective carriage-jack; and this object I attain in the manner which I will now proceed to describe, reference being had to the accompanying drawing, in which Figure 1 is a perspective view of the jack; Fig. 2, a side view; Fig. 3, a sectional plan on the line 1 2, and Fig. 4 a front View, drawn to an enlarged scale, of the disk with its spiral thread.

On the stand or frame A are cast two guiding-projections, a and a, for the lifting-bar B, on the front face of which is formed a rack composed of teeth I), and on the back a strengthening-rib, d. The form of this lifting-bar and of the guides for the saine will be best observed on referring to the sectional plan, Fig. 3. On an inclined shaft adapted to a bearing, 6, cast on the frame, is a disk, h,- and on the face of the latter is cast a spiral rib, i, for gearinginto the teeth of the lifting-bar in a manner too clearly shown in the drawing to need description. To the shaft which carries the disk h is secured a handle, H, by manipulating which the lifting-bar can be raised or lowered at' pleasure.

Independently of the general simplicity and cheapness of this jack, it possesses this advantage: That thelifting-baris retained in any position to which it may be adjusted without any appliances other than the spiral rib employed for raising and lowering the bar, for, the teeth of the latter bearing directly on this rib, no pressure on the bar can disturb it. In other words, the movement of the bar is under the sole control of the disk and its thread.

I wish it to be understood thatI do not claim the inclined disk with its spiral rib, in combination with the rack, irrespective of the entire structure; but that I claim as my invention The within-described carriage-jack, consisting of the stand A and its guides to a, the lifting-bar B and its rack adapted to the said guides, the inclined shaft, adapted to a bearing on the stand, and carrying an inclined disk with a spiral rib adapted to the teeth of the rack, all as set forth.

In testimony whereofI have signed my name to this specification in the presence of two subscribing witnesses.

JOHN G. BAKER.

Witnesses:

HUBERT HowsoN, HARRY SMITH. 

